In the lattice computation of the topological susceptibility $\chi$ of the QCD vacuum, a mixing with the action density operator $\left(\frac{g^2}{4{\pi }^2}\right)F_{\mu \nu }^a{F}_{\mu \nu }^a$ appears. In this paper we give a detailed calculation of this effect at one-loop order for infinite- as well as finite-size lattices.

• Received 22 February 1991

DOI:https://doi.org/10.1103/PhysRevD.44.513